It's totally true, even I've fallen victim to it in the past, but now I know about it I'm deliberately acting against it because I know no one else will help. Fun fact, if you're ever in trouble, pick people out of the crowd will increase your chances because you're separating them from the herd. You may not know their name but if you go "you with the red scarf and Hetalia bag help me!" You've increased your odds.

It's a psychological phenomenon. It does happen to everyone-- so trying to sound all cool and aloof about going against it just sounds like beansprout to me. Unless your socio-cultural sense is skewed or downright missing-- in which case you wouldn't even be here in the first place.

-well, I suppose it's just another byproduct of our [relatively] enhanced sense of awareness, so... ?

Your comment is generally applicable, I am not neurotypical and have already been in situations where others stand around. I always act as soon as I see an appropriate course of action, sometimes almost immediately. I have faced armed men, interfered when someone was being assaulted, prevented two drownings, and delivered first aid on several occasions including one where it prevented the loss of a limb.

People can train themselves or be trained to circumvent the bystander effect even if they are neurotypical though. Many people underestimate how much their wiring can interfere with their intentions and will until they experience it.

And what would be ways to train yourself into ignoring said effect?

Scenario training and simulation, not entirely different to what they use for paramedics and other first responders.

There are many reasons some people don't help just as there are reasons some people do help. Sometimes people may

be unaware of the full situation
not know what to do to help or think they can't help
fear they'll put themselves in danger (first aid training tells you to not put yourself in danger because you'll end up hurt and not being in a position to help anyone)
be in too much of a shock to react helpfully
be incapable of helping

There's a reason why people train to prepare for emergencies because it's just not guaranteed for people to react helpfully immediately if at all.

Then there's those who just don't care. Add to that those who've conditioned themselves not to respond to incidents.